Method of and apparatus for producing lead oxid.



E. BARTHELMESS.

METHOD or AND APPARATUS FDD PDDDucxNG LEAD ox|D.

APPLICATION FILED APR-25| |914. 1,204,537.. Patented Nov. 14, 1916.

Wzlwsses,

. i ,Em BAnTnELMEss, oENEUss oN REINE, GERMANY..

mETnon oF AND yArrnan'ilus 'non PEonUcINe Lam-.v exim.

- To all 'w-wm t may concern.

Be it known thatv I, EMIL BARTHELME'ss, engineer, a subject of the Emperor of Ger- -many, residing at 4 Breitestrasse, Neuss,

Germany, have invented new and useful Improvements in Methods of and Apparatusl for Producing Lead Oxid, of-which the followingvis a specification.

In thepreviou'sly known processes for the production of litharge, molten lead is atomized by suitable devices and is oxidized by means of a mixture of air and superheatedl steam, the air being sucked in by means of a' steam Vinjector and blown on to the surface of the molten lead. lThis has the disadvantage that the quantity of steafn which it is necessary to introduce for the complete oxidation, cannot4 be determined, so that in most cases it is necessary to work with an excess of steam, in consequence of which the leadl oxid exhibits va more or less high percentage of moisture. Moreover the apparatus which` work accordingto this method and which have a large oxidation chamber are arranged in an impracticable manner inasmuch as vit is very diiiicult to heat them uniformly. In consequence of th1s, incomplete oxidation andthe formation of incrustations on the inner surfaces of the oxidationchamber frequently result; in the latter case the removal of such incrustations can only be effected with .diliculty Furthermore the separation of the properly oxidized and badly oxidized lead can only be effected by the aid of particularly high oxidation chambers, which exhibit the last named defects in ,an especially high degree. A=ll these disadvantages are avoided by the present invention wherein cold water or water which has been previously heated'is used instead of steam. This water is introduced into the stream of gas necessary for oxidation drop by drop and in measurable quantities. In consequence of this the proportions of lead to be oxidized and water to be added, which are most favorable for the'oxidation, can be determined, while, on the other hand the whole 4 plant is considerably simplified by the omission of a steam generator or superheater re- I spectively.

The oxidation chamber is easily accessible and is heated uniformly on all sides by means of a fan-like stirring device, which is formed to closely fit the interior surface Vof the said oxidation chamber,. whereby any deposition of oxid on the heating surfaces Specification of Letters Patent. Application med April 25,1914. serial No. 834,426.

. atenteaNov. 14, 1916i is prevented andthe best conditions for oxidation are insured. The oxidizing stream of gas, which issucked in by the mixing de.- vice at the front end of the oxidationcham'- ber and which may consist of air, oxygen or any deslred mixture of oxygen, serves at the same time for the expulsion of the lead oxid dust which has been formed at the opposlte end. Before its entry into the oxidation chamber the said stream of gas may,

for the purpose of preliminary heating, be

led through suitable heating channels arranged in the brickwork of the heating apparatus and after leaving the oxidation chamber and depositing the lead oxid dust the said stream of gas may be brought back to the inletl through suitable pipes protected agalnst heat losses. The incompletely oxidized lead, which is deposited in the rear part of theoxid'ation chamber is returned to the bath of molten lead by means of the said mixing device. ,This mixing device serves thus on the one hand for atomizing the lead and for scraping `oii and conveying back the badly oxidized lead, while, on the other hand, itY causes the passage of a stream of gas through the apparatus, which stream contains ythe Jquantity of oxygen necessary for the oxidationland at vthe same time effects the separation of the lead oxid contaminated with metal from the l'thar'ge and the expulsion of the latter. 4

The .annexed drawing shows in vertical section one constructionalform of a device4 ,suitable for carrymg out'thefpresent process.

a is a pear-shaped containing vessel of iron Vor Iireproof material, whichis arranged in an inclined position and is tapered off toward one end. This containing vessel serves as an oxidation chamber and is in direct connection with a melting pot I), into 'which the, lead to be melted is introduced .1n the form of bars through lateral'openings c. The pot b, which is heated by means of a' suitableheatingdevice d, is completely surrounded, as is also the containing vessel a, by brlckwork in such a manner that the hot gases can spread over all the surfacesv of the apparatus Without hindrance and heat the same uniformly. v

A spindle e is mounted in the axis of the vessel a. This vspindle runs in bearings formed at the ends of the vessel a and is caused to rotate through the agency of a pulleyf vwhich is driven from any suitable a dropping device.

source of power. The spindle e is provided with a stirringv device which serves for atomizing the lead melted in the pot b. The said stirring device is formed so as to closely fit the inner surface of the oxidation 'cham- 1 ber. lThe stirring device consists of a centrifugal wheel g arranged at the front end of the spindle e in such a manner as to dip into the molten lead in the pot b, the rear part of the scraper comprising a series of conically disposed blades it. These blades and also the vanes of the centrifugal wheel,

are adapted to prevent the formation of a vthe stream ofl gas suiiiciently before itsadmission it is led through the inlet at Z into the heating channels lc formed in the brickwork and thence through the pipe m, through which latter the Water necessary 'for the' oxidation of the lead is introduced by means of a measuring vessel In. provided with l This arrangement renders it possible to regulate exactly thel proportion between the amount of lead to be oxidized ,and the necessary quantity of water to be added. f

The gas streaming through the oxidation chamber with increasing velocity carries the lead oxid which has been formed toward the outlet o at the opposite end, this outlet being connected to a transporting device p, by means of which the lead oxidl is conveyed away to suitable collecting funnels (not shown on the drawing). The dust which is also carried out with the litharge is deposited in the depositing chamber g, which is connected at r to a dust extracting plant. lf pure oxygen be employed as the oxidizing gas, then the depositing chamber g may be connected by means of 'a pipe S (shown in dotted lines) which is also protected against heat losses, to the pipe fm., in `order to return the unused oxygen to the inlet'i and'thus employ it again. lThis arrangement renders it possible at the same time to regulate the velocity of the vgas necessary to expel the lead oxid.

Claims:

1. The method of producing lead oxid consisting in atomizing molten lead vin a uniformly heated chamber, passing a stream of gas. containing oxygen through said chamber, adding water drop by drop in measured quantities to said gas, and drawingA oil' the gas with lead oxid dust in suspension; substantially as described.

2. The method of producing lead oxid consisting in atomizing molten lead in a uniformly heated chamber, passing a stream of gas containing oxygen lthrough said chamber7 adding water drop byv dropin measured quantities to said gas, drawing ofi the gas with lead oxid dust in suspension, and separating the lead oxid dust from the gas, substantially as described.

3. The method of producingv lead oxid consisting in atomizing molten lead in a uniformly heated chamber, passing a stream of gas containing oxygen through said chamber, adding water 4drop by drop in measured quantitiesl to said gas, drawing off the gas with the lead oxid dust in suspension, separating the lead oxid dust rom'the gas and repassing the gas through the chamber, substantially as described.

Ll. rThe method of producing lead oxid consisting in admitting heating gases to direct Contact with all the' outer surfaces of an oxidation chamber, passing a heated stream of gas containing oxygen through said chamber, adding water drop by drop in measured quantities to said stream, drawing oli'L the gays with the lead oxid dust in suspension, separating the dust from the gas, and regulating the velocity of the gas for expelling the oxid, substantially as described.

rl`he method of producing lead oxid consisting in atoniizing molten lead in a uniformly heated chamber, passing a stream of gas containing oxygen through said chamber, adding water dropby drop in measured quantities to said gas, drawing ol' the gas with lead oxid dust in suspension, and returning the unoxidized lead from the chamber back to the path; substantially as described.

6. Apparatus for producing lead oxid,

- comprising an oxidizing chamber, a molten lead bath in said chamber, and a mixing device having a` fan connected thereto and arranged in said chamber, said mixing device closely fitting the wallsv of the chamber, dipping into the bath of metal, and serving to suck in a stream of gas containing oxygen and scrape on and convey back to the molten bath the incompletely oxidized lead deposited on the walls of the chamber, substantially as described.

7. Apparatus for producing lead oxid, comprising a pear-shaped oxidizing chamber arranged in an inclined position and tapered oli' toward one end, a lead melting pot in direct communication with said' chamber, the said chamber and the said melting pot being inclosed in a common heating chamber, and means in said chamber for atomizing the lead in said chamber and for sucking in gas containing oxygen, substantially as described.

8.' Apparatus for producing lead oxid, comprising an inclined chamber having an oxidizing gas supply inlet at one end and an outlet at the opposite end, a molten lead bath in said chamber, a driving spindle extending centrally through said chamber, and a centrifugal Wheel on'said spindle which dips into the bath, of molten lead said oentrifugal Wheel. being made in the form of a fan, and being arranged directly adjacent to the gas inlet, substantially as-described.

9. Apparatus for producing lead oxid, comprising an inclined chamber having an oxidizing gas' supply inlet at one end and an outlet at' the opposite end, a molten lead bath at the inlet end, a driving spindle extending centrally through said chamber, a centrifugal Wheel on said spindle arranged opposite the gas inlet and adapted to dip into. said molten bath, and projecting blades on said Wheel arranged to closely fit ,the internal surface of the chamber, substantially as described.-

10. Apparatus for producing lead oxid, comprising an inclined chamber, a molten bath in said chamber,- a rotaryfan-like mixing device arranged in said chamber, said fan-like device. closely fitting the.walls ofv the chamber, and a gas supply to said chamber, said inclined chamber being surrounded by a heating chamber made of brickward and said gas supply being led through channels. vformed in said brickwork, substantially as described. v n

11. Apparatus for producing leadoxid, comprising an inclined conical chamber surrounded by a heating chamber made of brickwork, a molten bath in said chamber, a rotary fan-like mixing device arranged in said chamber opposite a gas supply opening.

andv adapted -to dip into said bath, gas supply channels inthe Walls of brickwork leading to said supply opening, a gas and lead oxid dust outlet, means for separating the gas from the lead oxid'dust, and means for returning,` the gas to the supply open:

ing, substantially as described.

atomizing the lead in said bath for causing av stream to be drawn 1n said chamber, and

12. Apparatus for producing lead oxid comprising an inclined conical chamber, a, molten lead bath in said chamber, means fora gas outlet at one end and a gas inlet atthe other end, a lead bath at lsaid inlet end, a fan-like mixingl device above said bath and adjacent to said lgas inlet, a Water supply pipeon the suction side of said fan, and

measuring devices in connection with said Water supply pipe, substantially as described.

14. Apparatus. for producing lead oxid comprising an-oxidizing chamber, a molten lead bathin said chamber, a gas inlet leading thereto,pmeans for atomizing the lead in said bath, means for sucking in a current of gas containing oxygen and admixed'with Water, said gas carrying off the lead oxid dust, and means for regulating the Velocity of the gas passing through the cham-ber.

V15. Apparatus for producing lead oxid, comprising an oxidizing chamber having a gas inlet, a molten lead bath in said chamber,'a suction fan arranged in front of said gas inlet, a Water supply pipe, and means for regulating the amount of Water passing through said pipe, vsubstantially as described.

16. Apparatus for producing lead oxid comprising a chamber, means for uniformly heating said chamber, a pot for melting lead in said chamber, means for passing a stream of gas through said chamber, means for adding Water in measured quantities to said gas, and means for drawing off! the gas with a lead oxid dust; substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

EMIL BARTHELMESS.

Witnesses: ,Y

HELEN NUFER, ALBERT Noren. 

